1. Field
One or more example embodiments relate to an optical communication device, and more particularly, to an arrayed waveguide grating (AWG).
2. Description of Related Art
In optical communications, wavelength-division multiplexing (WDM) is a transmission method that may allocate a plurality of signals to different wavelength bands, and simultaneously transmit the signals through a single optical fiber. An arrayed waveguide grating (AWG) may be necessary for the WDM, and include an arrayed waveguides (also referred to as a waveguide array herein) including a plurality of waveguides having different lengths each. The AWG may distribute a light signal to each of the waveguides based on each wavelength, and may multiplex or demultiplex the light signal using a difference among light paths based on the different lengths of the waveguides.
A loss and a crosstalk may occur due to a phase error while a plurality of light signals is passing through the waveguides. The phase error of the light signals passing through the AWG may occur due to, for example, a distortion of a radiation pattern at an input port of the AWG, a distortion occurring in a boundary between the waveguide array and a free propagation region, and a distortion occurring due to an interference among the waveguides included in the waveguide array. To correct such a phase error, a method of eliminating the aforementioned causes while maintaining a difference in length among the waveguides is used.